chapter ten part one

Question 1

2 types of organisms

Answer 1

heterotrophs and autotrophs

Question 2

autotrophs

Answer 2

“self-feeders”
- sustain themselves w/o eating anything
- producers - ultimate source of organic molecules

Question 3

heterotrophs

Answer 3

unable to make own food, live on compounds produced by other organisms
- consumers - herbivores, carnivores, decomposers (fungi/prokaryotes)

Question 4

chlorophyll

Answer 4

green pigment that gives leaves color
- in thylakoid membranes

Question 5

mesophyll

Answer 5

tissue in interior of leaf
- 30-40 chloroplasts per mesophyll cell
- thylakoid

Question 6

thylakoid

Answer 6

membranous sacs
- grana - columns of thylakoids

Question 7

stomata

Answer 7

microscopic pores typically on underside of leaf where CO2 enters and O2 leaves

Question 8

photosynthesis balanced equation

Answer 8

6CO2 + 6H2O + light –> C6H12O6 + 6O2

Question 9

who tested splitting of water?

Answer 9

Van Noel by substituting S for O
- challenged the false theory that O2 came from CO2 rather than H2O

Question 10

process of light reactions

Answer 10

1. chlorophyll absorbs a photon, and the electron becomes very excited
2. a water molecule is split, providing source of electrons and giving off O2
3. excited electrons fall down ETC (PSII, Pq, Cato, Pc, PSI, NADP+ final electron acceptor)
4. NADP+ becomes reduced to NADPH
5. as energy is released by ETC, H+ ions accumulate in lumen
6. H+ gradient used to power ATP synthase, (photophorylation)

Question 11

photophorylation

Answer 11

excited electron fall down chain, energy released pumps H+ ions into lumen, which drive ATP synthase

Question 12

what does light reaction produce?

Answer 12

O2, NADPH, ATP

Question 13

what does the Calvin Cycle need?

Answer 13

CO2, NADPH, ATP

Question 14

overview of Calvin Cycle

Answer 14

CO2 from air incorporated into organic molecules by carbon fixation, NADPH reduces fixed carbon to carbohydrate

Question 15

where does the light reaction occur?

Answer 15

thylakoid membrane

Question 16

where does the Calvin Cycle occur?

Answer 16

stroma

Question 17

sunlight

Answer 17

electromagnetic energy that travels in waves from the sun

Question 18

wavelength of visible light

Answer 18

380-750 nm

Question 19

photons

Answer 19

act like objects/particles w/ fixed quantities of energy

Question 20

pigments

Answer 20

absorb visible light

Question 21

what light does chlorophyll absorbs?

Answer 21

red and blue, reflects green

Question 22

spectrophotometer

Answer 22

measurement of ability of pigments to absorb various wavelengths of light

Question 23

2 spectrums of spectrophotometer

Answer 23

absorption spectrum and action spectrum

Question 24

absorption spectrum

Answer 24

graph plotting pigment’s light absorption vs. wavelength

Question 25

action spectrum

Answer 25

profiles relative effectiveness of different wavelengths of radiation and confirms visible light spectrum of chlorophyll - illuminates chlorophyll, then plots wavelength against photosynthetic rate

Question 26

chlorophyll a

Answer 26

key light-capturing pigment that participates directly in light reactions

Question 27

chlorophyll b

Answer 27

accessory pigment to chlorophyll a

Question 28

carotenoids

Answer 28

separate group of accessory pigments - hydrocarbons that are various shades of yellow/orange, absorb violet/blue-green light - broaden color spectrum of photosynthesis

Question 29

how do carotenoids broaden the color spectrum of photosynthesis?

Answer 29

1. absorb/dissipate excessive light energy that would damage chlorophyll 2. interact w/ O2 to form reactive oxidative molecules

Question 30

reaction center and light center

Answer 30

look on paper

Question 31

excitation of chlorophyll

Answer 31

absorbing photon boosts electron to orbital of higher energy, pigment molecule in excited state - drops back, emits photon and heat (fluorescence)

Question 32

fluorescence

Answer 32

afterglow where protons are given off

Question 33

Photosystem I

Answer 33

- P700 - absorbs light w/ wavelength of 700 nm (far red) - comes second

Question 34

Photosystem II

Answer 34

- P680 - absorbs light w/ wavelength of 680 nm (red) - chlorophyll a at reaction center - comes first

Question 35

difference between PSI and PSII

Answer 35

- identical chlorophyll a molecules - associate w/ different proteins which affects electron distribution and light absorption

Question 36

noncyclic electron flow

Answer 36

1. PSII absorbs light 2. electrons taken from water - O2 produced 3. electrons more from PII to PI via carriers 4. ATP made as electrons move to PI (chemiosmosis) 5. 2nd absorption of light in PI raises e to higher level 6. ferredoxin (Fd) carries electron to NADP_

Question 37

ferredoxin (Fd)

Answer 37

protein that carries electron to NADP+ in ETC

Question 38

carriers that move electrons from PII to PI

Answer 38

- plastoquinione (Pq) - cytochromes - Plastocyanin (Pc)